Re: Does exponential acceleration affect measurement of light speed?

andrewspencers@xxxxxxxxx wrote: 
An observer will measure a constant speed of light from a fixed light
source regardless of his velocity relative to the light source, but
does this hold true even if the observer is accelerating?

Here by "observer" you mean "reference frame"; I'm pointing this out because in the next paragraph you use the same word in a different sense.

With respect to a uniformly accelerating reference frame (Rindler coordinates), light doesn't generally travel at the speed c, nor does it generally travel in straight lines.

How about if
even the acceleration is increasing, or even increasing exponentially?

In this case there isn't a well-defined macroscopic reference frame with respect to which the measurement can be made. One can consider a reference frame covering a thin tube surrounding the worldline of an arbitrarily moving pointlike object; in this case the light will only stay within the bounds of the reference frame for a short time, during which time the acceleration of the object may be treated as constant, and one gets the same speed measurements as for the uniformly accelerating case.

Do the answers remain the same if instead the observer is fixed and the
light source is accelerating?

As you've set things up in this paragraph, there is an asymmetry between the emitter (which is pointlike) and the receiver (which is a reference frame). If the reference frame is inertial and the light source accelerating, the measured speed will always be c.

Second paragraph:

Also, if a light source is unidirectional, at rest relative to an
observer, positioned at a distance from the observer, and pointing at
the observer, then the observer can see the light, regardless of the
light source's (and thus also the observer's) velocity relative to
anything else.


Yes. Here by "observer" you mean a pointlike object receiving the light.

However, if both the light source and the observer are
accelerating at the same rate, in the same direction, with that
direction being perpendicular to the line between them, and the
direction in which the light source is pointing still coincides with
the line between the light source and the observer, then although
they're still at rest relative to each other and the light source is
still pointing at the observer, the observer can no longer see the
light, right?


Yes.

Do all of these results hold if the observer and light source are
moving through water instead of through empty space? (Besides the fact
that the measured speed of light will be lower.)


Yes, I think so. Also in various aether and emission theories.

-- Ben
.

Relevant Pages

  • Re: The IRT transform equations
    ... From observer A's point of view the transforms are as follows: ... Lambda=wvaelength of the standard light source in A's frame as ... measures his standard light source to have the same wavelength. ... The diffraction grating doesn't care what the ...
    (sci.physics.relativity)
  • Re: The IRT transform equations
    ... From observer A's point of view the transforms are as follows: ... Lambda=wvaelength of the standard light source in A's frame as ... measures his standard light source to have the same wavelength. ...
    (sci.physics.relativity)
  • Does exponential acceleration affect measurement of light speed?
    ... An observer will measure a constant speed of light from a fixed light ... does this hold true even if the observer is accelerating? ... light source is accelerating? ...
    (sci.physics)
  • Re: DOPPLER EFFECT IN EINSTEIN ZOMBIE WORLD
    ... the light source emits light towards the observer and this light has ... The wavelength remains constant ... frequency to find the relative speed of the wave to the observer. ...
    (sci.physics)
  • Re: Basics Series I: NEWTON, MAXWELL, EINSTEIN HOAXES - REVEALED!
    ... >> does bring the sun closer at a velocity of about 232 ... >> space observer will see longer wavelengths, ... >> are observing the same light source. ... >> 400 nm bluelight wave coming from a source broadcasting ...
    (sci.physics)